[plankk]

http://nernst.chem.metu.edu.tr/icho2011/files/IChO2011%20Prep%20problems%20with%20solutions%20110215.pdf  (page 80)

I tried to do on my own task 29 however I have no idea why in products B1 and B2 both substituents are cis. I suppose that they will be rather trans. Is there any kind of model (like Felkinh-Anh) which is able to explain it?

[discodermolide]

http://nernst.chem.metu.edu.tr/icho2011/files/IChO2011%20Prep%20problems%20with%20solutions%20110215.pdf  (page 80)

I tried to do on my own task 29 however I have no idea why in products B1 and B2 both substituents are cis. I suppose that they will be rather trans. Is there any kind of model (like Felkinh-Anh) which is able to explain it?

Looks like a 2+2 cycloaddition to me, which gives the cis beta lactam

[AlbertoA]

here's a stupid question, Problem 27 part c
Why do the cyclohexa 1,3- diene gives only one product when 1 equivalent of mCPBA, wouldn't t produce a racemic mixture?

[BluePill]

It's just the same molecule even if you flip it.

[AlbertoA]

aaaaaa!! yes!!! My bad 

[orgopete]

here's a stupid question, Problem 27 part c
Why do the cyclohexa 1,3- diene gives only one product when 1 equivalent of mCPBA, wouldn't t produce a racemic mixture?

I agree with you. The product shown is a 1R,2S. There is no reason a 1S,2R product should not also accompany it.